1. Field of the Invention
The present invention relates to a disc apparatus for reproducing and writing data on a data recording disc in a photomagnetic recording type minidisc cartridge.
2. Prior Art
In recent years, disc cartridges in which a data recording disc is housed in a protecting cartridge (which will be hereinbelow denoted simply as a cartridge have been proposed. A photomagnetic recording type minidisc cartridge, as one example of this kind of cartridges, is shown in FIG. 11. In FIG. 11 cartridge 100 incorporates a cartridge casing 101, a data recording disc 102 housed in the cartridge casing 101, a disc access hole 106 formed at one side of the cartridge casing 101, and a slide shutter 104 for opening and closing the disc access hole 106. Further, cartridge gripping recesses 105 are formed at the left and right sides on the front side of the rear surface of the cartridge casing 101, and a longitudinal groove 106 is formed in the right end face of the cartridge casing 101 and receives a shutter engaging member (which is not shown) in its intermediate part. This shutter engaging member is urged toward the groove 106 by a spring (which is not shown), that is, it can be retracted. Further, this shutter engaging member is linked to the above-mentioned slide shutter 104.
Further, data is recorded in or reproduced from this cartridge by means of a disc apparatus in which an optical pick-up records or reproduces data while it moves radially of the data recording disc 102 with a predetermined gap between the optical pick-up and the data recording disc 102, and accordingly, it is necessary to eliminate vibrations transmitted from the outside. To this end a movable chassis (suspension chassis) for holding the optical pick-up is supported in a floating condition on a stationary chassis by means of resilient members. Further, this movable chassis is normally fixed to the stationary chassis by means of a lock mechanism which does not belong to a loading mechanism, except that the disc cartridge is set at a position other than a recording/reproducing position.
Further, in this disc apparatus, as shown in FIGS. 12 and 13a-c, a holder 110 for loading and ejecting the cartridge 100 is provided with a shutter closing spring 112, as shown in FIG. 12, having an engaging part 111 which is adapted to be engaged in a shutter opening and closing hole 108 formed in the slide-shutter 104 so as to close the slide-shutter 104 upon ejection of the disc cartridge 100.
Further, in this disc apparatus, as shown in FIGS. 13a to 13c, a loader shift mechanism has a rack member 120 on which a loader 109 is mounted, and a gear 122 meshed with a rack tooth part 121 of the rack member 120 and coupled to a pinion of a drive motor through the intermediary of a drive gear train. Further, when the gear 122 is rotated through the drive gear train, the rack member 120 which is meshed with the gear 122 through the rack tooth part 121 thereof, is moved, and accordingly the loader 109 is shifted.